A key satellite used in predicting severe weather in the eastern United States, including Atlantic hurricanes, has failed.

Last Tuesday evening, the imaging system on the weather satellite known as GOES-East ceased to transmit images.

Engineers in the satellite division of the National Oceanic and Atmospheric Administration, which operates the satellite, are working to determine the cause of the problem, said Tom Renkevens, the deputy division chief of the satellite products and services division at the agency.

The geosynchronous satellite, which sits above the Earth at 75 degrees longitude, is used in forecasting severe weather and is very useful for predicting the tracks of Atlantic hurricanes, since it has a clear view of the Atlantic Ocean.

On Thursday morning, due to the failure of GOES-East, NOAA activated its spare GOES satellite. That satellite, known as GOES-14, is kept hovering above the Earth at 105 degrees longitude, which is more to the west of the current GOES-East satellite.

The other satellite in the constellation, known as GOES-West, hovers at 135 degrees longitude and watches over the western United States and the Pacific Ocean.

James Franklin, chief of hurricane forecast operations at the National Hurricane Center, said that for the time being, using GOES-14 will suffice for the agency's hurricane predictions.

Busy season predicted
NOAA has predicted twice as many hurricanes as normal this season (ClimateWire, May 24).

However, because the location of the GOES-14 satellite is more westerly than that of GOES-East, the images it takes of the part of the Atlantic that includes the western Antilles and the eastern Caribbean are very distorted, Franklin said.

This distortion would inhibit the center's ability to track hurricanes forming in that area, around Puerto Rico and the Dominican Republic.

Luckily, said Franklin, although hurricane season begins in a week, hurricanes in that part of the Atlantic do not start forming until later in the season in July, August and September.

"We are fortunate as to the time of year that this occurred. It could have been worse if it occurred two months from now," Franklin said.

If the broken GOES-East satellite is not repairable, NOAA's satellite service has the option to move the GOES-14 backup satellite eastward to take the place of its broken one, Renkevens said.

"We're ready; we can move it," he said.

Previous repairs have worked
A European satellite known at Meteosat-10 also takes images of the Atlantic Ocean, from a more easterly position at zero degree longitude and is used by U.S. weather forecasters, as well.

NOAA has long used images from other countries' satellites in its weather prediction and will continue to do so, Renkevens said.

Last September, the GOES-East satellite also experienced a failure and the backup GOES-14 satellite was activated, but engineers were able to fix that problem. Renkevens said there was no indication yet that the current failure was related to last year's.

NOAA makes a practice of keeping a spare satellite flying in the air between the operating GOES-East and GOES-West satellites, in case of such a failure.

However, if the GOES-East satellite is not repairable, the agency will use up its spare. The next GOES satellite, part of a new sequence of geostationary orbiting satellites used in weather prediction, is not scheduled to launch until October 2015.

Renkevens said their hope is to repair the GOES-East satellite as soon as possible.

While the satellites are overall very reliable due to multiple redundancies in their design, when something does go wrong, it's often like solving a changing puzzle. "It's not like, oh, there goes the transmission again. It's always something unique, something different," Renkevens said.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500